---
layout: docs
page_title: Domain Model - Sessions
description: |-
  The anatomy of a Boundary session
---

# Sessions

A session is
a set of related [connections][]
between a [user][] and a [host][].
A session may include a set of [credentials][]
which define the permissions granted to the [user][] on the [host][] for the duration
of the session.

A user initiates a session
by requesting access to a [target][].
If a user has the proper [permissions][],
a session is created
and the [expiration time][] and [connection limit][]
are set based on the [target's attributes][].
If the [target][] is associated with [credential libraries][],
[credentials][] are retrieved and returned from each
[credential library][].
A snapshot of the data
relevant to authorizing the session
is also captured and stored in the Boundary data warehouse
when the session is created.

Sessions are created in the [project][] of the corresponding [target][].
Deleting a project will terminate all of the active sessions in the project
but will not effect any session data in the data warehouse.
Historical data in the data warehouse is never deleted.

## Termination

A session is forcefully terminated when one of the following occurs:

- The session reaches the time limit and expires.

- An authorized user manually cancels the session.

- Any resource associated with the session is deleted
  or removed from the [target][].
  This includes: the [host][], the [host set][], the [host catalog][],
  a [credential][], a [credential library][], a [credential store][],
  the [target][] itself, the [project][], the [organization][],
  the [user][], the user's [account][], or the account's [authentication method][].

In addition to the above,
a session terminates non-forcefully
when the user closes all connections
and no additional connections are allowed
because of a connection limit.

Any [credentials][] associated with the session are revoked when the session is
terminated.

Permissions are only evaluated at session establishment.
Changes to a user's permissions do not effect existing sessions.

## Referenced By

- [Project][]
- [Credential][]
- [Host Set][]
- [Target][]

[expiration time]: /boundary/docs/concepts/domain-model/targets#session_max_seconds
[connection limit]: /boundary/docs/concepts/domain-model/targets#session_connection_limit
[target's attributes]: /boundary/docs/concepts/domain-model/targets#tcp-target-attributes
[account]: /boundary/docs/concepts/domain-model/accounts
[accounts]: /boundary/docs/concepts/domain-model/accounts
[authentication method]: /boundary/docs/concepts/domain-model/auth-methods
[authentication methods]: /boundary/docs/concepts/domain-model/auth-methods
[connections]: /boundary/docs/concepts/domain-model/session-connections
[credential library]: /boundary/docs/concepts/domain-model/credential-libraries
[credential libraries]: /boundary/docs/concepts/domain-model/credential-libraries
[credential store]: /boundary/docs/concepts/domain-model/credential-stores
[credential stores]: /boundary/docs/concepts/domain-model/credential-stores
[credential]: /boundary/docs/concepts/domain-model/credentials
[credentials]: /boundary/docs/concepts/domain-model/credentials
[host catalog]: /boundary/docs/concepts/domain-model/host-catalogs
[host catalogs]: /boundary/docs/concepts/domain-model/host-catalogs
[host set]: /boundary/docs/concepts/domain-model/host-sets
[host sets]: /boundary/docs/concepts/domain-model/host-sets
[host]: /boundary/docs/concepts/domain-model/hosts
[hosts]: /boundary/docs/concepts/domain-model/hosts
[target]: /boundary/docs/concepts/domain-model/targets
[targets]: /boundary/docs/concepts/domain-model/targets
[user]: /boundary/docs/concepts/domain-model/users
[users]: /boundary/docs/concepts/domain-model/users
[organization]: /boundary/docs/concepts/domain-model/scopes#organizations
[organizations]: /boundary/docs/concepts/domain-model/scopes#organizations
[project]: /boundary/docs/concepts/domain-model/scopes#projects
[projects]: /boundary/docs/concepts/domain-model/scopes#projects
[permissions]: /boundary/docs/concepts/security/permissions

## Service API Docs

The following services are relevant to this resource:

- [Session Service](/boundary/api-docs/session-service)

## Tutorial

Refer to the [Manage Sessions with HCP Boundary](/boundary/tutorials/hcp-administration/hcp-manage-sessions) tutorial to learn how to start, view, and cancel a session.
